1. Field of the Invention
The present invention relates generally to computer boot procedures, and more specifically, a method and system for booting a plurality of servers from a single operating system image.
2. Background Art
Conventional network boot methods suffer from two fundamental drawbacks. First, they maintain a separate image for each remote system to boot from. Typically, the separate images are mirrors of a ‘Master’ image. The primary problem with this ‘Master image’ method is that unnecessary drive space is used—in many cases extensively—to maintain duplicate boot files. This unnecessary redundancy may result in increased memory/storage cost, increased architectural overhead, and an increased propensity of disk failure. In addition, complicated mirroring scripts and methods may be required to ensure uniformity across all copies of the Master image. Setup times for new systems are also typically longer and more complicated.
Second, conventional network boot methods are commonly used only for numerically-intensive or high-performance computing applications. In such arrangements, individual computers do not maintain their own identity. Instead, they act as a plurality ‘CPU host’ exploited for their processing ability. Thus, machines booted from those types of single image concepts are not able to maintain a separate identity and purpose from the other units.
One boot methodology is the OpenSSI clustering system from Hewlett Packard. This methodology uses a single drive image to boot multiple disparate machines having separate purposes. However, this methodology uses a clustered file arrangement where a separate system maintains the file system, all machines have full read/write access, and the separate system controls collisions and prevents multiple writes to the same file on the file system at the same time by the disparate machines. More information regarding the OpenSSI clustering system is available at www.openssi.org.
Another boot methodology is the Linux Terminal Server Project (“LTSP”). With LTSP, the entire file system is in memory and the initial image is provided during boot-up through BIOS using a “boot from network” option. Once booted, no hard drives are shared by any client terminals. More information regarding the LTSP is available at www.ltsp.org.